This invention relates to an engine control system and method and more particularly to an improved sensor and sensor condition determining arrangement for such a system.
A wide variety of types of control systems have been proposed for improving the efficiency and performance of internal combustion engines. Basically, these systems sense a variety of engine running and ambient conditions and control such things as the fuel air ratio and ignition timing. These systems take a wide variety of types and form and frequently employ combustion condition sensors which sense the actual fuel air ratio and through a feedback control system adjust the fuel air ratio to maintain the desired value. Of course, other types of sensors and other types of systems are employed.
One of the actual parameters of the engine that is frequently measured for these control systems is the position of the throttle control for the engine. By determining the throttle control position such factors as engine load, operator demand or intake air flow can be determined. Generally, the throttle control sensor is a potentiometer that is associated with a component of the throttle control for determining its position.
In many types of systems, the throttle control is a butterfly-type valve that is positioned in a throttle body for the engine. The potentiometer that measures the throttle valve position is frequently mounted on the actual throttle body. This, however, gives rise to a location and mounting that can cause the sensor to deteriorate in operation. In any event, since this is an important control parameter for most types of engine controls, accuracy in the sensed information is essential.
Therefore, a principal object of this invention to provide an improved sensor and mounting arrangement and method for determining accuracy of the throttle position.
It is a further object of this invention to provide an improved method for checking the throttle position sensor and providing information in the event the sensor is operating abnormally.